Commit c94b1f96 authored by Geliang Tang's avatar Geliang Tang Committed by David S. Miller
Browse files

mptcp: send out checksum for MP_CAPABLE with data 



If the checksum is enabled, send out the data checksum with the
MP_CAPABLE suboption with data.

In mptcp_established_options_mp, save the data checksum in
opts->ext_copy.csum. In mptcp_write_options, adjust the option length and
send it out with the MP_CAPABLE suboption.

Co-developed-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarGeliang Tang <geliangtang@gmail.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 06fe1719

net/mptcp/options.c

+43 −9
Original line number Diff line number Diff line
@@ -439,6 +439,7 @@ static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb, 
	struct mptcp_sock *msk = mptcp_sk(subflow->conn);

	struct mptcp_ext *mpext;

	unsigned int data_len;

	u8 len;



	/* When skb is not available, we better over-estimate the emitted

	 * options len. A full DSS option (28 bytes) is longer than
@@ -474,10 +475,16 @@ static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb, 
		 * packets that start the first subflow of an MPTCP connection,

		 * as well as the first packet that carries data

		 */

		if (data_len > 0)

			*size = ALIGN(TCPOLEN_MPTCP_MPC_ACK_DATA, 4);

		else

		if (data_len > 0) {

			len = TCPOLEN_MPTCP_MPC_ACK_DATA;

			if (opts->csum_reqd) {

				opts->ext_copy.csum = mpext->csum;

				len += TCPOLEN_MPTCP_DSS_CHECKSUM;

			}

			*size = ALIGN(len, 4);

		} else {

			*size = TCPOLEN_MPTCP_MPC_ACK;

		}



		pr_debug("subflow=%p, local_key=%llu, remote_key=%llu map_len=%d",

			 subflow, subflow->local_key, subflow->remote_key,
@@ -1122,6 +1129,25 @@ static void mptcp_set_rwin(const struct tcp_sock *tp) 
		WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);

}



static u16 mptcp_make_csum(const struct mptcp_ext *mpext)

{

	struct csum_pseudo_header header;

	__wsum csum;



	/* cfr RFC 8684 3.3.1.:

	 * the data sequence number used in the pseudo-header is

	 * always the 64-bit value, irrespective of what length is used in the

	 * DSS option itself.

	 */

	header.data_seq = cpu_to_be64(mpext->data_seq);

	header.subflow_seq = htonl(mpext->subflow_seq);

	header.data_len = htons(mpext->data_len);

	header.csum = 0;



	csum = csum_partial(&header, sizeof(header), ~csum_unfold(mpext->csum));

	return (__force u16)csum_fold(csum);

}



void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,

			 struct mptcp_out_options *opts)

{
@@ -1129,14 +1155,17 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 
	     OPTION_MPTCP_MPC_ACK) & opts->suboptions) {

		u8 len, flag = MPTCP_CAP_HMAC_SHA256;



		if (OPTION_MPTCP_MPC_SYN & opts->suboptions)

		if (OPTION_MPTCP_MPC_SYN & opts->suboptions) {

			len = TCPOLEN_MPTCP_MPC_SYN;

		else if (OPTION_MPTCP_MPC_SYNACK & opts->suboptions)

		} else if (OPTION_MPTCP_MPC_SYNACK & opts->suboptions) {

			len = TCPOLEN_MPTCP_MPC_SYNACK;

		else if (opts->ext_copy.data_len)

		} else if (opts->ext_copy.data_len) {

			len = TCPOLEN_MPTCP_MPC_ACK_DATA;

		else

			if (opts->csum_reqd)

				len += TCPOLEN_MPTCP_DSS_CHECKSUM;

		} else {

			len = TCPOLEN_MPTCP_MPC_ACK;

		}



		if (opts->csum_reqd)

			flag |= MPTCP_CAP_CHECKSUM_REQD;
@@ -1159,8 +1188,13 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 
		if (!opts->ext_copy.data_len)

			goto mp_capable_done;



		if (opts->csum_reqd) {

			put_unaligned_be32(opts->ext_copy.data_len << 16 |

					   mptcp_make_csum(&opts->ext_copy), ptr);

		} else {

			put_unaligned_be32(opts->ext_copy.data_len << 16 |

					   TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);

		}

		ptr += 1;

	}